Exchange hybrid mail flow question

Kenny Stern 141 Reputation points
2023-07-09T00:21:22.7533333+00:00

Currently we have hybrid set up between our Exchange on-prem and Exchange Online. All mailboxes have been migrated to Exchange Online and we are only using the internal Exchange servers for SMTP relay. We would like to remove the hybrid set up but continue to use the Exchange servers for SMTP.

Can this be done?

If so, how would we configure this? Would we have to manually configure the send connector in Exchange and the receive connector in Exchange Online?

Are there advantages or disadvantages to removing the hybrid and doing it manually?

Is there something other than Exchange on-prem that would be better to use for SMTP relay. The main goal is to simplify the environment. We have many internal servers that have a need to relay mail for things like alerts, etc. However, it really doesn't seem like we need hybrid anymore.

Thank you.

Microsoft Exchange Online
Exchange Server
Exchange Server
A family of Microsoft client/server messaging and collaboration software.
1,448 questions
Exchange Server Management
Exchange Server Management
Exchange Server: A family of Microsoft client/server messaging and collaboration software.Management: The act or process of organizing, handling, directing or controlling something.
7,793 questions
Microsoft Exchange Hybrid Management
Microsoft Exchange Hybrid Management
Microsoft Exchange: Microsoft messaging and collaboration software.Hybrid Management: Organizing, handling, directing or controlling hybrid deployments.
2,233 questions
{count} votes

Accepted answer
  1. Andy David - MVP 152.3K Reputation points MVP
    2023-07-09T15:09:51.5566667+00:00

    If you all you need is SMTP relay then consider IIS Server with SMTP added or an Edge role server ( that isnt subscribed to an AD domain)

    Having said that, keeping the existing the Exch Servers is fine as well. To set to allow relay follow this and ensure that the Exchange Servers ARE NOT accessible outside of your network on port 25, that would be really bad.

    https://learn.microsoft.com/en-us/exchange/mail-flow/connectors/allow-anonymous-relay?view=exchserver-2019

    Note, if you are still syncing from on-prem to Azure, you can not remove that last Exchange Server regardless unless you follow specific steps and are at the latest Exchange 2019 CU

    https://learn.microsoft.com/en-us/exchange/decommission-on-premises-exchange

    0 comments No comments

0 additional answers

Sort by: Most helpful

Your answer

Answers can be marked as Accepted Answers by the question author, which helps users to know the answer solved the author's problem.